What causes the CO (carbon monoxide) to be higher in your exhaust? I failed state inspection again for the same reason after reconnecting my O2 sensor and repairing a crack in the head-pipe.
I don't just wanna shot-gun parts, but is there anyway I can isolate what's wrong without getting too expensive? I'm leaning towards a bad O2 sensor, b/c my CAT is only 4 years old at this point, 2 of which it sat in the garage. I don't think it's a clogged fuel injector b/c I change my fuel filters often and always use injector cleaner at every 3,000 mile oil change.
Any thoughts / suggestions? Everything else is well within range, but the CO is several times the allowed limit. I'm not happy at all b/c now I can't drive my Jeep anywhere until I get it fixed